/*
 * Browser-compatible JavaScript MD5
 *
 * Modification of JavaScript MD5
 * https://github.com/blueimp/JavaScript-MD5
 *
 * Copyright 2011, Sebastian Tschan
 * https://blueimp.net
 *
 * Licensed under the MIT license:
 * https://opensource.org/licenses/MIT
 *
 * Based on
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.2 Copyright (C) Paul Johnston 1999 - 2009
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */
export function md5(bytes: string | Uint8Array) {
	if (typeof bytes === 'string') {
		const msg = unescape(encodeURIComponent(bytes)) // UTF8 escape

		bytes = new Uint8Array(msg.length)

		for (let i = 0; i < msg.length; ++i) {
			bytes[i] = msg.charCodeAt(i)
		}
	}

	return md5ToHexEncodedArray(wordsToMd5(bytesToWords(bytes), bytes.length * 8))
}

const hexTab = '0123456789abcdef'

/*
 * Convert an array of little-endian words to an array of bytes
 */
function md5ToHexEncodedArray(input: number[]): number[] {
	const output: number[] = []
	const length32 = input.length * 32

	for (let i = 0; i < length32; i += 8) {
		const x = (input[i >> 5] >>> i % 32) & 0xff

		const hex = parseInt(hexTab.charAt((x >>> 4) & 0x0f) + hexTab.charAt(x & 0x0f), 16)

		output.push(hex)
	}

	return output
}

/**
 * Calculate output length with padding and bit length
 */
function getOutputLength(inputLength8: number): number {
	return (((inputLength8 + 64) >>> 9) << 4) + 14 + 1
}

/*
 * Calculate the MD5 of an array of little-endian words, and a bit length.
 */
function wordsToMd5(x: Uint32Array, len: number): number[] {
	/* append padding */
	x[len >> 5] |= 0x80 << len % 32
	x[getOutputLength(len) - 1] = len

	let a = 1732584193
	let b = -271733879
	let c = -1732584194
	let d = 271733878

	for (let i = 0; i < x.length; i += 16) {
		const oldA = a
		const oldB = b
		const oldC = c
		const oldD = d

		a = md5ff(a, b, c, d, x[i], 7, -680876936)
		d = md5ff(d, a, b, c, x[i + 1], 12, -389564586)
		c = md5ff(c, d, a, b, x[i + 2], 17, 606105819)
		b = md5ff(b, c, d, a, x[i + 3], 22, -1044525330)
		a = md5ff(a, b, c, d, x[i + 4], 7, -176418897)
		d = md5ff(d, a, b, c, x[i + 5], 12, 1200080426)
		c = md5ff(c, d, a, b, x[i + 6], 17, -1473231341)
		b = md5ff(b, c, d, a, x[i + 7], 22, -45705983)
		a = md5ff(a, b, c, d, x[i + 8], 7, 1770035416)
		d = md5ff(d, a, b, c, x[i + 9], 12, -1958414417)
		c = md5ff(c, d, a, b, x[i + 10], 17, -42063)
		b = md5ff(b, c, d, a, x[i + 11], 22, -1990404162)
		a = md5ff(a, b, c, d, x[i + 12], 7, 1804603682)
		d = md5ff(d, a, b, c, x[i + 13], 12, -40341101)
		c = md5ff(c, d, a, b, x[i + 14], 17, -1502002290)
		b = md5ff(b, c, d, a, x[i + 15], 22, 1236535329)

		a = md5gg(a, b, c, d, x[i + 1], 5, -165796510)
		d = md5gg(d, a, b, c, x[i + 6], 9, -1069501632)
		c = md5gg(c, d, a, b, x[i + 11], 14, 643717713)
		b = md5gg(b, c, d, a, x[i], 20, -373897302)
		a = md5gg(a, b, c, d, x[i + 5], 5, -701558691)
		d = md5gg(d, a, b, c, x[i + 10], 9, 38016083)
		c = md5gg(c, d, a, b, x[i + 15], 14, -660478335)
		b = md5gg(b, c, d, a, x[i + 4], 20, -405537848)
		a = md5gg(a, b, c, d, x[i + 9], 5, 568446438)
		d = md5gg(d, a, b, c, x[i + 14], 9, -1019803690)
		c = md5gg(c, d, a, b, x[i + 3], 14, -187363961)
		b = md5gg(b, c, d, a, x[i + 8], 20, 1163531501)
		a = md5gg(a, b, c, d, x[i + 13], 5, -1444681467)
		d = md5gg(d, a, b, c, x[i + 2], 9, -51403784)
		c = md5gg(c, d, a, b, x[i + 7], 14, 1735328473)
		b = md5gg(b, c, d, a, x[i + 12], 20, -1926607734)

		a = md5hh(a, b, c, d, x[i + 5], 4, -378558)
		d = md5hh(d, a, b, c, x[i + 8], 11, -2022574463)
		c = md5hh(c, d, a, b, x[i + 11], 16, 1839030562)
		b = md5hh(b, c, d, a, x[i + 14], 23, -35309556)
		a = md5hh(a, b, c, d, x[i + 1], 4, -1530992060)
		d = md5hh(d, a, b, c, x[i + 4], 11, 1272893353)
		c = md5hh(c, d, a, b, x[i + 7], 16, -155497632)
		b = md5hh(b, c, d, a, x[i + 10], 23, -1094730640)
		a = md5hh(a, b, c, d, x[i + 13], 4, 681279174)
		d = md5hh(d, a, b, c, x[i], 11, -358537222)
		c = md5hh(c, d, a, b, x[i + 3], 16, -722521979)
		b = md5hh(b, c, d, a, x[i + 6], 23, 76029189)
		a = md5hh(a, b, c, d, x[i + 9], 4, -640364487)
		d = md5hh(d, a, b, c, x[i + 12], 11, -421815835)
		c = md5hh(c, d, a, b, x[i + 15], 16, 530742520)
		b = md5hh(b, c, d, a, x[i + 2], 23, -995338651)

		a = md5ii(a, b, c, d, x[i], 6, -198630844)
		d = md5ii(d, a, b, c, x[i + 7], 10, 1126891415)
		c = md5ii(c, d, a, b, x[i + 14], 15, -1416354905)
		b = md5ii(b, c, d, a, x[i + 5], 21, -57434055)
		a = md5ii(a, b, c, d, x[i + 12], 6, 1700485571)
		d = md5ii(d, a, b, c, x[i + 3], 10, -1894986606)
		c = md5ii(c, d, a, b, x[i + 10], 15, -1051523)
		b = md5ii(b, c, d, a, x[i + 1], 21, -2054922799)
		a = md5ii(a, b, c, d, x[i + 8], 6, 1873313359)
		d = md5ii(d, a, b, c, x[i + 15], 10, -30611744)
		c = md5ii(c, d, a, b, x[i + 6], 15, -1560198380)
		b = md5ii(b, c, d, a, x[i + 13], 21, 1309151649)
		a = md5ii(a, b, c, d, x[i + 4], 6, -145523070)
		d = md5ii(d, a, b, c, x[i + 11], 10, -1120210379)
		c = md5ii(c, d, a, b, x[i + 2], 15, 718787259)
		b = md5ii(b, c, d, a, x[i + 9], 21, -343485551)

		a = safeAdd(a, oldA)
		b = safeAdd(b, oldB)
		c = safeAdd(c, oldC)
		d = safeAdd(d, oldD)
	}

	return [a, b, c, d]
}

/*
 * Convert an array bytes to an array of little-endian words
 * Characters >255 have their high-byte silently ignored.
 */
function bytesToWords(input: Uint8Array): Uint32Array {
	if (input.length === 0) {
		return new Uint32Array([])
	}

	const length8 = input.length * 8

	const output = new Uint32Array(getOutputLength(length8))

	for (let i = 0; i < length8; i += 8) {
		output[i >> 5] |= (input[i / 8] & 0xff) << i % 32
	}

	return output
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safeAdd(x: number, y: number): number {
	const lsw = (x & 0xffff) + (y & 0xffff)
	const msw = (x >> 16) + (y >> 16) + (lsw >> 16)
	return (msw << 16) | (lsw & 0xffff)
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function bitRotateLeft(num: number, cnt: number): number {
	return (num << cnt) | (num >>> (32 - cnt))
}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function md5cmn(q: number, a: number, b: number, x: number, s: number, t: number): number {
	return safeAdd(bitRotateLeft(safeAdd(safeAdd(a, q), safeAdd(x, t)), s), b)
}

function md5ff(a: number, b: number, c: number, d: number, x: number, s: number, t: number): number {
	return md5cmn((b & c) | (~b & d), a, b, x, s, t)
}

function md5gg(a: number, b: number, c: number, d: number, x: number, s: number, t: number): number {
	return md5cmn((b & d) | (c & ~d), a, b, x, s, t)
}

function md5hh(a: number, b: number, c: number, d: number, x: number, s: number, t: number): number {
	return md5cmn(b ^ c ^ d, a, b, x, s, t)
}

function md5ii(a: number, b: number, c: number, d: number, x: number, s: number, t: number): number {
	return md5cmn(c ^ (b | ~d), a, b, x, s, t)
}
